Liners for material crushing and grinding mills



Aug. 28, 1951 D. WESTON r LINER FOR MATERIAL CRUSHING AND GRINDING MILLS F iled Nov. 5, 1947 3 Sheets-Sheet 1 INVENTOR DAVID WESTON ATTORN EY A g.28, 19 L D. WEsfoN 2 ,566,103

LINER FOR MATERIAL CRUSIX-IILING AND GRINDING MILLS Filed Nov. 5,1947. 7 J Shets-Sheet s INVEN TOR DAVID WESTON B ;W-%///ZAM ATTORNEY Patented Aug. 28, 1951 LINERS FOR MATERIAL CRUSHING AND GRINDING MILLS David Weston, Toronto, Ontario, Canada Application November 5, 1947, Serial No. 784,162 6 Claims. (Cl. 241-481) This invention relates to an improved liner for ball mills; combined impact shattering, crushing and grinding mills; and like apparatus for reducing materials such as ores and the like.

In the reduction of material in ball mills, combinded impact shattering, crushing and grinding mills and other apparatus commonly used, the liner elements are exposed to severe wearing action, particularly on the high points or ribs of the liners which are employed to decrease slippage of the charge and increase the lifting effect in the rotation of the mill. As a result of this excessive wear on the liners, it is necessary to design the liner sections for replacement after relativelyshort periods of use. Also, of course, the rapid wear on the liner elements contaminates the products of the apparatus, and as the high points of ribs continue to wear, the efficiency of the'apparatus is progressively reduced with increasing sliming and an increasing percentage of coarsest sizes in the product.

An important object of this invention is to provide a liner element for ball mills; combined impact, shattering, crushing and grinding mills, and like apparatus for the reduction of materials such as ores and the like, which presents wearing surfaces to the abrasive action of the material in the apparatus, which are extremely hard and highly resistant to' wear, and which is designed to retain generally its original configuration during the several phases of its life, and which does not appreciably impair the quality of the product or the rate of production from the apparatus over its useful life.

-A further important object of the invention is to provide a liner for material reduction mills oi the class described which reduces substantially the slippage of ore, and ball or rod charge, if any, in the mill and thus in addition to improving the rate of production and the quality of the product, serves to reduce a heretofore important source of wear on the liner.

A further object of the invention is to provide a liner for a material reduction mill of the class described which by reason of its novel design and arrangement of parts may be constructed much thinner in section than the liners of the prior art without any impairment of the life of the liner, and substantially reducing the fixed overall weight of the mill and substantially increasing the capacity of the mill.

A still further object of the invention is to provide a liner for material reduction mills of the class described in which the liner parts exposed to the greatest wear are provided with wearing surfaces of increased thickness whereby the same overall dimensions are retained, and thus to provide a liner in which all liner parts may be replaced at the same time.

An understanding of the manner in which the above and other objects of the invention are attained may be had from the following description, reference being made to the accompanying drawings, in which:

Figure 1 is a perspective view, partly broken away, of the end of a combined impact shattering, crushing and grinding mill incorporating the liner elements of the present invention;

Figure 2 is an end elevati-onin section of the apparatus illustrated in Figure 1 employing a ball charge and illustrating the arrangement of the liner elements and the distribution of the feed material and ball charge;

Figure 3 is a perspective view of part of a ring liner employed in the ends of the apparatus illustrated in Figures 1 and 2 and incorporating the improvements of the present invention;

Figure 4 is a perspective view of part of an end liner suitable for use in a conventional ball mill; 1

Figure 5 is a perspective view of a shell liner suitable foruse in a conventional ball mill;

Figure 6 is a perspective view of a section of a shell liner suitable for use in the combined impact shattering, crushing and grinding apparatus illustrated in Figures 1 and 2.

Figures 7 and 8 are end views of modifications in the arrangement of the ribs;

Figure 9 is a perspective view of a section of the deflector ring employed in the apparatus i1- lustrated in Figures 1 and 2;

Figures 10 and 11 are end views of alternative arrangements of the ribs of the shell liner;

Figure 12 is a perspective view of a lifter bar used in combination with the shell liner;

Figure 13 is an end view of a shell liner and lifter bar assembly;

Figure 14 is a plan view of an alternative arrangement of a sectional shell liner; and

Figure 15 is a perspective view of a pair of the sectional shell liners illustrated in Figure 14.

Like reference characters refer to like parts throughout the specification anddrawings.

Referring to the drawings, the numeral 20 indicates an apparatus for reducing materials such as ores, and is of the combined impact shattering, crushing and grinding, rotatable drum type such as described and illustrated in my co-pending application, United States patent application Se- 3 rial No. 749,131, filed May 20th, 1947 now Patent No. 2,555,171, May 29, 1951.

A material reduction mill of this type is preferably provided with deflector plates 2! arranged in a circular ring around the inlet and. outlet openings to deflect charge and partly processed material to the centre of the drum. The end ring liner 22, Figure 1, is positioned between the deflector plate and the horizontal wall and the shell liner 23, and bars 24 are held in place against the horizontal wall of the drum.

The high parts of the several plates and liner elements are exposed to the highly abrasive and shattering action of the material charged into the apparatus and the constant tumbling and grinding of the charge material or the mixture of charge material and ball charge in the drum. As a result, the surfaces of these parts normally tend to wear rapidly with adverse effect on the productivity and efficiency of the apparatus in addition to the cost attendant to frequent replacement.

I have found that by designing the high and low parts of these elements in staggered relation and by capping them with material which is extremely hard and resistant to wear it is possible to'overcome the disadvantages normally inherent in and associated with such mills;

An enlarged view of a section of the deflector plate is illustrated in Figure 9. This section is The top or exposed surface 21 is slotted, as in-.

dicated by the numeral 28, the slots extending, substantially equi-spaced, with their axes at a minor angle to the vertical end face of the drum to which the section is secured. Preferably, all the parts exposed to the abrasive action of the charge, such as the top surface of the section and the bottom surface. of the slots, are capped with a hard, wear resistant material-such as tungsten carbide, or a mixture consisting essentially of tungsten carbide, or a tungsten alloy, .or other material having like hard, wear resisting properties. The high and low spots of the deflector sections are in staggered relation and are capped Wuhan-extremely hard, wear resistant material.

The ring liner 22 is also formed with alternate high ribs 32 and low ribs 31. The high ribs are capped with hard, wear resisting material 90, such as tungsten carbide while the low ribs 31 are preferably formed of strips of tungsten carbide. The ribs 32 and SI function principally to pre vent slippage of the charge annd serve to retain the charge in the main body of the mill'where it is exposed to the impact shattering, crushing and grinding actions. The ring liner may be secured to the end of the drum such as by bolts extended through the bolt holes 33. In new liner, the high ribs are exposed to the abrasive action of the charge with very little, if any, wear on the lower ribs 31. .As the capping en wears down, the material below the capping wears rapidly and ribs 3! begin to function to retain the charge in a live state.

Figures 4 and '2 illustrate respectively perspective and end views of an alternative modification of a ring liner in which the spaces 41 between the ribs are capped with hard, wear resistant material to provide, in' efiect, an arrangement of alternate high and low ribs in which the exposed surfaces are capped with tungsten carbide to protect them from the abrasive action of the charge material. In this modification of the rib arrangement, the highest ribs 6!, andthe intermediate ribs 52, are both capped with tungsten carbid ea while a strip of tungsten carbide 60 is attached to the liner in the spaces 4| between the ribs. The function of the ribs 60, 51 and 62 in this modification is the same as that described hereinabove.

Figures 5 and 8 illustrate respectively perspective and end views of an alternative modification of a shell liner, such as may be employed in a ball mill. The spaces Ma between the ribs are capped with tungsten carbide to provide an ar-' rangement of high ribs 61a, intermediate ribs 62a and low ribs did all presenting a hard, wear resistant surface Add in the manner described above.

The horizontal surface of the drum is provided with a shel1 liner 23 liftingrand crushing bars 24. The shell liner is shaped generally to fit snugly against the interior wall of the drum, overlapping the bases of the bars 24 as illustrated in Figures 2 and 13, and is provided with alternate high and low ribs-52 and 153 respectively. These ribs are capped with wear resisting material 58, such as tungsten carbide. a

The bar 2% serves the dual function of lifting the charge and crushing the particles of the charge and is in the form of an elongated raillike structure having a head 54, and a base 55 joined by a web 55 which is tapered inwardly towards the base. out in and extends longitudinally of th head. Theexposed surfaces of the head and :the channel are capped with extremely hard, wear re-' sistant material 58 such as that described hereinabove. I

The she'll liner and bar assembly are secured to the horizontal surface of the drum, such 'as by bolts, and preferably, as illustrated in Figure 13, are arranged in sections with the longitudinal edges of the shell liner '5! overlapping the bases 55 of the bars as.

The arrangement of the high and low ribs 52 and 53 of the shell liner and the bars .24 serve to maintain the charge on rotation of the drum in a live condition to obtain the maximum impact shattering, crushing and grinding effect.

The ribs i0 and H of the liner I 3 illustrated in Figure 10 are of staggered height and the exposed surfaces of the ribs and the :spaces 12 between the ribs are capped with hard, wear resistant material such as described hereinbefore.

The ribs !5 of the liner H illustrated "in Figure H extend approximately the same distance beyond the liner and the surface of the ribs and the spaces '56 between the ribs are capped by hard, wear resistant material such as described hereinbefore.

The shell liner 80, illustrated by Figures '14 and 15 is particularly applicable for' use with a ball or pebble mill. The liner is formed with upstanding, spaced apart ribs 8! whichmay be of the same or staggered heights. In this type of mill, the Wear is most rapid on the parts of the mill adjacent to the inlet end, due to the greater abrasiveness of the coarse feed material which gradually decreases in size as it passes through the mill with progressively decreasing abrasive efiect. Therefore, a saving maybe effected in the amount of capping necessary to ensure a long life for the liner by tapering the thickness of'the capping from the inlet end of the mill to the outlet end, the capping being Preferably, a channel .51 :is a

thickest or heaviest adjacent to the inlet end. The, spaces 83 between the ribs 8| may be capped in amanner similar to the capping of the ribs.

In the operation of a material reduction mill incorporating the liner elements of the present invention, feed material is,.-introduced into the mill through a feed opening, preferably centrallydisposed in one end of the mill. The feed material is directed by the deflector ring, formed of sections 2|, into the body. of the mill. The faces of the deflector sections exposed to the wearing action of the charge material are protected by a capping of wear resistant material and by the arrangement of channels 28, present wearing surfaces which involve only about 50% of the entire exposed surface of the deflector lining. When new, there is very little wear on capped surfaces of the channels 28. As the capping 21 on the uppermost surfaces of the deflector sections wears through, the material underneath the capping wears rapidly to below the capping of the channels 28, and that capping then presents a wearing surface to the charge material.

The high and low ribs of the ring liner are so spaced apart that any particles which would tend to slip, for example, when the mill rotating faster than individual particles, are forced to drop into the body of the millwhere they are trapped in the body of the charge. As in the case of the deflector sections 2|, only a fraction of the total surface area of the ring liner is exposed to the abrasive action of the charge material at any one time through the staggered arrangement of the ribs.

The shell liner and bar assembly serves the functions of maintaining the charge in a live condition, lifting particles of the charge to the top of the drum to fall on the body of the charge ass rts the ribs oriented radially thereof, the combination of said liners being effective for lifting,

the internal cylindrical wall of said shell, ribs below, and crushing and grinding particles of the charge. As in the cases of the deflector sections and ring liner described above, only a fraction of the total surface area of the bars 24 and the shell liner are exposed at any one time to the highly abrasive action of the charge.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. In a rotatable material reduction mill comprised of a cylindrical shell having an annular inlet end and an annular outlet end, a liner comprising a base secured to the internal cylindrical Wall of said shell, ribs of staggered height upstanding from said base and extending from end to end of said shell and oriented parallel to the shell axis, and a ring-like liner formed of sub stantially wedge-shaped blocks attached at their bases to the annular ends of the shell and having channelled faces oriented radially thereof, the combination of said liners being effective for lifting, crushing and grinding the material being processed in said mill.

2. In a rotatable material reduction mill comprised of a cylindrical shell having an annular inlet end and an annular outlet end, a liner com: prising a base detachably secured to the internal cylindrical wall of said shell, ribs of staggered height upstanding from said base and extending from end to end of the shell and oriented parallel to the shell axis, combined lifting and crushing bars extending parallel to and higher than the ribs and spaced substantially equi-distant around the wall of said shell and extending from end to end thereof, and a ring-like liner having upstanding ribs attached to each annular end with of staggered height upstanding from said base and extending from end to end of said shell and oriented parallel to the shell axis, combined lifting and crushing bars extending parallel to and higher than said ribs and spaced substantially equi-distant around the cylindrical wall of said shell and extending from end to end thereof between the sections of said base liner, and aringlike liner formed of substantially wedge-shaped blocks attached at their bases to each annular end of the shell with channelled faces oriented radially thereof, the combination of said liners being effective for lifting, crushing and grinding the material being processed in said mill.

4. In a rotatable material reduction mill comprised of a cylindrical shell having an annular inlet end and an annular outlet end, a liner comprising a base secured to the internal cylindrical wall of said shell, ribs of staggered height upstanding from said base and extending from end to end of said shell and oriented parallel to the shell axis, and a ring-like liner for each annular end wall formed of substantially wedgeshaped blocks attached at their bases to the end wall, each wedge-shaped block having substantially equi-spaced channels in its exposed face oriented radially of the end Wall, the combination of said liners being effective for lifting, crushing and grinding the material being processed in said mill.

5. In a rotatable material reduction mill comprised of a cylindrical shell having an annular inlet end and an annular outlet end, a liner comprising a base secured to the internal cylindrical wall of said shell, ribs upstanding from said base and extending from end to end of said shell and oriented parallel to the shell axis, and a ringlike liner for each annular end wall formed of substantially wedge-shaped blocks attached at their bases to the end wall, each wedge-shaped block having substantially equi-spaced channels in its exposed face oriented radially of the end wall, the combination of said liners being eflective for lifting, crushing and grinding the material being processed in said mill.

6. In a rotatable material reduction mill comprised of a cylindrical shell having an annular inlet end and an annular outlet end, a liner comprising a base detachably secured to the internal cylindrical wall of said shell, combined lifting and crushing bars upstanding from said base and extending from end to end of the shell and oriented parallel to the shell axis, a ring-like liner for each annular end wall formed of substantially wedge-shaped blocks attached at their bases to the end wall, each wedge-shaped block having substantially equi-spaced channels in its exposed base oriented radially of the end wall, and a ringlike liner having radially oriented upstanding ribs attached to each annular end wall between the wedge-shaped liner and the uppermost faces of the combined lifting and crushing bars, the combination of said liners being effective for lifting,

crushing and grinding the material being processedin said mi-ll.

DAVID WESTON.

REFERENCES CITED 2 v 5 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 10 939,637 Rotherham Nov. 9, 1909 1,083,400 Hansen et; a1 Jan. 6, 1914 1,109,459 P'osselt Sept. 1., 1914 1,169,276 NeviIl Jan. 25,1916 1,207,174 Johnson Dec.v 5, 1916 15 1,295,290 Fasting Feb. 25, 1919 1,309,210 Marcy July 8, 1919 Number Number Name Date Haushalter Aug. 8, 1933 Abrams Mar. 19, 1940 Tankersley Apr 8, I941 Holland-Letz June 124, 1941 Rachner Mar. 10, 1942 FOREIGN PATENTS Country Date Sweden Feb. '12, 1910 Australia Great Britain Jan. I7, 1907 OTHER REFERENCES Resisto-Loy Co. advertisement, Rock product's, January 1947, page 38. 

